Spreader stoker



June 30, 1953` 7 E. c. MILLER 2,643,782

SPREADER s'roxER Filed March 18. 1948 [que C. MILLER Arron/ver Patented June 30, 1953 afiliarse .fyi SPREADER stroken Earle C.- Miller,` Worcester, Mass., assignorto -Riley Stoker Corporation, Worcester, Mass., a

corporationy of` Massachusetts Appiicauqnmarch 18, 1948, serial No. 15,638

1 I f y This inventiony relates to spreader stokers, and y"more particularly to a stoker' having means whereby the operator may determine'thequa'n- Y -tity of fuel'which has been supplied tothe furfrom, anoverhead bunker through a downspout,

and metering devices have. been kinstalled in such downspouts'. However, such devices are Asubject to `error because of variations/in the' fuel level -in the hopper at the time of reading themeter. Furthermore, they tendto obstruct the flow of the fuel, vand they are exposed.y to considerable l abrasive wear. In many installationsI n'odownspouts are employed.

It is accordingly one object of the invention to provide a spreader stoker having simple, inexsolaims. (o1. 21e-18.28)

front of the plate I I there is mounted a spreader stoker comprising a casing I4 having a horizontal rotatable bladed distributor I5` thereinin position to throw fuel rearwardly through thel opening I2 rirltowthe furnace. Aboveand in frontof the distributor there is mounted a hopper,` I6, open at the bottom, from4 which fuelflow's yhy gravity `to a rsubstantially horizontal plate kI'I spaced therebeneath." A"ra`m I9 vis slidably mounted ony the top of the plate I'I and arranged to be reciprocated by a rocker armZIl, whereby fuel will be moved rearwardly along the plate I1 and caused to spill from the rear edge thereof onto the-distributor I5. In accordance with`wellknown practice, any suitable means maybe n"em-4 i ployed to controlr the ratel of fuel feed by"vary pensive and accurate mechanism for metering y the fuel which is sup-plied to the stoker distributor. e

Itis a further object of the invention to provide a spreader Stoker having a fuel metering mechanism which will operate in a proper manner for long periods without appreciable wear.

It is arfurt'her object of the invention to provide a spreader stoker having a fuel metering mechanism which will operate entirely independently of any downspout or other means employed for filling the stoker hopper.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

Referring to the drawings illustrating one embodiment of the invention, and in which like reference numeralsindicate like parts,

Fig, 1 is a vertical section through a spreader stoker, taken on the line I-I of Fig. l2; and

Fig. 2 is a section taken on the line 2 2 of Fig. 1, partially broken away for clearness of illustration.

The embodiment illustrated comprises a furnace wall I0A having the usual metal front plate II and a fuel admission opening I2. On the ing` the stroke or speed 'of vthe ram* I9. '1,The distance between 'the plate II and the loweredge of the rear walljl ofthe hopper determines the depth' or thickness of thel streamof fuel moving rearwardly. This lower edgeis preferably formed by a cut-off plate 22 mounted onv the main body vof the hopper andr constituting the lowerportion rof the rear hopper wall. g V` YFor the purpose of metering thel fuel supplied -to ,thedistributor 15,- a .biased wheerfzi'isrro- .'tatab-lyl mounted behind the plate 22; ink position to be driven by the rearwardly traveling fuel' stream. Preferably there are two of these wheels 24, spaced a short distance apart axially, and.

connected by a common horizontal shaft 25.'

This shaft 25 is rotatably supported in a bearing 26 on the lower end of an upright arm 28 which is pivotally connected at itsupper end to vavhinge member 29 attached to the plate 22. From this hinge member the arm` 28 extends downwardly for a short distance incontact with the rear surface of the plate 22 and thence rearwardly to, the bearing 26. such that the lowermost blades of the wheels 2l normally extend slightly below the plate 22 to engage the fuel stream, but if an excessive force should be applied to these wheels by a foreign body or byv a large lump of fuel the arm 28 will swing rearwardlyfand upwardly, thus avoiding any damage to the parts. The wheels 24 are connected by means of a flexibleshaft or cable 30 to a revolution counter 3| of 'well-known con# struction mounted on a bracket 32 on one side of the casing I4. This counter is located later-r ally beyond the hopper I6 where it can be easily read from the firing aisle.

The operation of the invention will now be apparent from theabove disclosure. As the ram I9 reciprocates, a stream of fuel from the hopper The construction is I6 will move rearwardly in an intermittent manner along the plate I'I and fall from the rear edge thereof onto the rapidly revolving distributor I5, which will throw the fuel through the opening I2' into the furnace. This fuel stream will be of a predetermined width and of a predetermined depth, the width being a function of the casing Width, and the depth being a function of the distance between the plate II and the lower edge of the plate 22. The upper portion of the fuel stream will engage the bladed wheels 2| and rotate them, the number of revolutions being recorded by the counter 3|. It is a simple matter to calibrate the apparatus by weighing the fuel required to produce a given number of revolutions of the wheels. Thereafter, with the stokers in service, the operator can easily ascertain the feeding rate by noting the change in the reading of the counter 3| over a known interval of time.

It is found that the apparatus provides accurate metering of the fuel despite considerable Variation in the feeding rate. Furthermore, changes in the moisture content of the fuel have no pronounced leffect on the accuracy of the metering. The

hinged mounting of the arm 28 protects the wheels 24 from damage by foreign bodies or large lumps of fuel. If the stoker is shut down by stopping the ram I9, the operator can Swing the arm 28 upwardly and rearwardly to move the wheels 24 out of the path of radiant heat from= the opening I2.

The apparatus is simple, inexpensive, and well adapted for its intended purpose.

Having thus described my invention, what I claim as new and desire to secure by Letters Pat- "f5 ent is:

1. A spreader Stoker comprising a rotatable fuel distributor, a fuel hopper located above and in front of the distributor, mechanism to feed fuel rearwardly from the bottom of the hopper to the .1

being mounted for movement about an axis parallel to and spaced from its axis of rotation.

2. A spreader Stoker comprising a fuel distributor rotatable about a horizontal axis, a substantially horizontal plate located above and in front of the distributor, a fuel hopper located above the plate and having a rear wall with its lower edge spaced from the plate, a ram reciprocable in a forward and rearward direction beneath the hopper to feed fuel along the plate rearwardly from the hopper and beneath the lower edge of the said rear wall in a stream of predetermined width and depth, the stream spilling from the rear edge of the plate onto the distributor, a bladed wheel rotatable about a horizontal axis behind the hopper and extending slightly below the said lower edge in position to be rotated by its engagement with the upper portion of the fuel stream, and a revolution counter connected to the wheel, said wheel being mounted for movement about an axis parallel to and spaced from its axis of rotation.

3, A spreader Stoker as set forth in claim 2, in which the wheel is rotatably supported on the lower end of an upright arm which is pivotally connected at its upper end to the rear wall of the hopper, the revolution counter being connected to the wheel by a flexible shaftVand the arm being free to swing rearwardly and upwardly ifan excessive force is applied to the wheel by the fuel stream.

EARLE C. MILLER.

References cited in the fue of this patent UNITED STATES PATENTS 

